In this paper, we propose a novel pairing-free certificateless scheme that utilizes the state-of-the-art blockchain technique and smart contract to construct a novel reliable and efficient CLS scheme. Then we simulate the Type-I and Type-II adversaries to verify the trustworthiness of our scheme. Security analysis as well as performance evaluation outcomes present our design can hold more reliable security assurance with less computation cost (i.g., reduced by around 40.0% at most) and communication cost (i.g., reduced by around 94.7% at most) than other related schemes. IEEE